


Heartbeats

by there_must_be_a_lock



Category: Supernatural
Genre: M/M
Language: English
Status: Completed
Published: 2020-01-20
Updated: 2020-01-20
Packaged: 2021-02-27 08:35:11
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 935
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22340401
Author URL: https://archiveofourown.org/users/there_must_be_a_lock/pseuds/there_must_be_a_lock
Summary: More and more Cas begins to wonder what the fuck his Father was thinking, when he designed humans. None of this makes sense.
Relationships: Castiel & Dean Winchester, Castiel/Dean Winchester
Comments: 7
Kudos: 41





	Heartbeats

Cas knows what a heartbeat _is_ , of course.

He’s always known the mechanics of it, since back when the thing was first designed: blood collects in the atria, the atria contract and move blood into the ventricles, the ventricles contract and send blood either to the lungs or out to the rest of the body, and the human continues to breathe and live and function just as Castiel’s Father intended them to. It’s a neat little system.

Castiel enjoys listening to the heartbeats of the humans around him. It’s soothing, somehow. He can hear the way the muscles squeeze and the blood rushes and the whole contraption goes thump- _thump_ thump- _thump_ in a steady even beat.

He knows that heartbeats can change, too. Oxygen, panic responses, all that. Again, he knows the mechanics. But it’s a different thing altogether to _hear_ it, when he starts to get to know Sam and Dean.

He’s never really been this _close_ to emotions before. Emotions had always been such an abstract concept. The angels generally agree that human emotions are a design flaw; they can’t quite understand why their Father had invented them in the first place, not that they’d ever criticize. Castiel knows he should be tolerant, because the poor humans can’t exactly help how they were built, but part of him always wonders why the humans don’t just _control_ their emotions. It doesn’t make sense.

So it’s _strange_ , when he gets to know Sam and Dean. It’s strange to hear the way their hearts sometimes beat faster. At first he thinks it happens at random. It takes him some time to connect the change in rhythm with a surge of emotion. He can hear the way Sam’s heart beats faster when he knows Dean is in trouble. He can hear the way Dean’s heart beats faster when he gets angry… but Dean’s angry so often that it takes him some time to notice the _other_ pattern.

Cas blips into the back of the car and takes them by surprise, and he hears the change, and he realizes with some surprise that _he_ can affect their heartbeats. It makes sense, he just never quite put it together like that. It feels strangely intimate, to have a direct effect on a human’s basic functioning… and he also finds it entertaining, if he’s being honest.

So Cas will show up and sometimes they’ll be startled by it, and their bodies will show all the usual symptoms, but Sam’s heartbeat slows, after a few minutes. His body regulates itself. It returns to its normal pace, a steady sixty-five beats per minute, unless they’re fighting or arguing or whatever else.

Dean’s heartbeat is less predictable, and for a long time Castiel can’t figure out _why_. Sometimes he’ll see Dean’s eyes on him, and he’ll hear the way his pulse speeds up slightly. Sometimes Cas stands too close, still; he’s learning, but sometimes he misjudges, and he notices that Dean’s heart races, usually, just before he reminds Cas about personal space. 

When they start to become closer, Cas notices that Dean’s heart pounds hard and fast when they hug. He thought it was a species-wide anomaly, at first, but Sam’s heartbeat seems unaffected when Cas hugs him.

Cas brushes it off, eventually. It’s just another thing he’ll never understand about humans in general and Dean in particular. It’s just one more thing about Dean Winchester that doesn’t make sense.

And then Cas becomes human. He loses his grace, and he becomes human, and he can’t hear _other_ heartbeats, any more, but he’s newly conscious of his own, and it’s… it’s _strange_. Emotions feel so different than he expected.

The first time he hears Dean’s voice, thin and fuzzy through the phone, Cas’s pulse starts racing. His skin feels strangely hot and there’s a new unfamiliar swooping sensation, low in his stomach. It’s disorienting. Cas feels happy, he supposes? But not _just_ happy.

It’s all very complicated, suddenly. Everything seems to be complicated, where the Winchesters are concerned, but Cas didn’t think his own body would be so affected. The more time he spends with humans, the less they make sense.

When he sees Dean again, Cas’s heart feels like it’s about to burst through his ribcage. He blames it on joy, at first. He’s home, he’s with his friends… this must be what joy feels like. But it happens the next time, too, and the next. It happens every fucking time he looks at Dean.

More and more Cas begins to wonder what the fuck his Father was thinking, when he designed humans. _None_ of this makes sense.

When he finally realizes, it’s not a big sudden beautiful moment. It’s just another day. Cas walks in and Dean’s slumped over the table nursing a beer. He has dark circles under his eyes, his lips are chapped, he looks like _shit_ , overall, and when he gives Cas a tired little half-smile, Cas just thinks, _oh. Oh, I see._

He sits down. Dean’s talking, but Cas isn’t listening, not really. He’s too busy trying to hear Dean’s heartbeat over the pounding of his own.

Eventually he gives up; his human ears aren’t up to the task. He just reaches out and wraps his fingers around Dean’s wrist, and Dean goes silent, eyes wide. He tries to force a laugh.

“Cas?” he asks hesitantly.

Cas brushes his fingers over bluish veins and finds Dean’s pulse. Cas smiles, helplessly, and feels the way Dean’s heartbeat kicks up even faster, blood pumping under thin fragile skin.

When their lips finally meet, everything starts to make sense.


End file.
